DE19650825A1 - Process for the reduction of sulfur and vat dyes - Google Patents

Abstract

This invention concerns a process for reducing dyes of the group consisting of sulfur and vat dyes. The reduction is carried out in an aqueous alkali medium using isomaltulose or a mixture containing isomaltulose as the reducing agent.

Description

The invention relates to a method for reducing tion of dyes from the group consisting of Sulfur and vat dyes.

Process for dyeing cellulosic textile materials with sulfur and vat dyes substances are known. Both Küpen- and Schwe fur dyes must be before or during of the dyeing process from its water-insoluble form by reduction into a water-soluble, fibrous fine form, the so-called leuco shape, is transferred to anyone the. It is known as a reducing agent Na use triumdithionite or sodium sulfide. The However, they have the disadvantage that in particular a so-called for more sensitive dyes Overreduction occurs, which leads to the Dyes after reduction and application to the Textile material does not return to the desired pigment can be oxidized. In addition, the burden sulfide ions put the environment through uncomfortable Odors and their toxicity. From DE 41 15 452 A1 it is known to use vat dyes with fructose, Reduce mannose or glucose. From the EP 0 699 797 A2 discloses sulfur dyes using fructose, galactose, glucose, mannose, mal reduce tose or lactose. The one in these  Publications described reduction of the dye fe with the help of reducing sugars the advantage that the negative, on the release from environmental influences based on sulfide ions that will. Due to the low redox potential, for example of glucose, it is able to to reduce most of the dyes used ren, while at the same time the risk of over-reduction on is avoided. Ever turns out to be disadvantageous but the comparatively slow setting of the Redox potential equilibrium. The under aid Coloring of the sugar mentioned above procedures require due to the described un advantageous reduction kinetics a comparison wise long period used to reduce the dyes.

The basis of the present invention So the technical problem is a process for the reduction of vat and sulfur dyes to make available the aforementioned Overcomes disadvantages, especially ecologically unsafe is conceivable a wide range of commercially available Dyes can reduce the risk of overreaction avoids production and an improved reduction has kinetics.

The basis of the present invention technical problem is ge by means of the method solved according to main claim. Accordingly, the He a process for the reduction of dyes from the group consisting of sulfur dyes  and vat dyes, the reduction in aqueous alkaline medium with isomaltulose or their mixture with other reducing sugars, especially trehalulose containing reduction medium is carried out. The use of iso maltulose, in particular a trehalulose held mixture with isomaltulose, as a reduction medium in the reduction of sulfur dyes and vat dyes of the water-insoluble form in the water-soluble leuco form has the advantage that the redox potential balance of Isomaltulose, especially of mixtures that the contain sugar, eat much faster represents than in the conventionally used Sugar. The faster setting of the redox pot tial equilibrium allows in more advantageous Way a shortened reduction phase in Dyeing textile materials, which ultimately leads to Leads to cost savings. That according to the invention seen reducing agent is ecologically harmless Lich, has a low redox potential, so that practically all commercially available dyes redu can be decorated, and does not lead to their over reduction.

In connection with the present invention who the dyes under sulfur dyes understood those made by cooking chemical compounds in Polysulfides or can be obtained in sulfur nen. In connection with the present invention are meant by vat dyes  those that are considered derivatives of anthraquinone can be.

The invention provides as a reducing agent Iso maltulose, especially a mixture of these Contains sugar. Particularly preferred ter way contains the reducing agent in addition to Iso maltulose additionally trehalulose, isomaltose, sac charose, glucose, fructose or carbohydrate oli gomere. In particular, the invention relates to a Reducing agent, the 10 to 90 wt .-% trehalulose, 10 to 90 wt% isomaltulose, 0 to 15 wt% sac charose, 0 to 20% by weight fructose, 0 to 20% by weight Glucose, 0 to 5% by weight isomaltose and 0 to Has 5 wt .-% carbohydrate oligomers. In front Partly, isomaltulose can be included producing reducing agents by adding sucrose enzymatically rearranged to isomaltulose and isomal tulose is largely separated, so that a non-separated isomaltulose and trehalulose ent holding product is obtained. The manufacturing wise and composition of an isomaltulose and Mixture containing trehalulose is used in EP 0 625 578 A1 described, which with regard to the the above-mentioned aspects are part of the inventions essential disclosure of the present Er is. The reducing agent according to the invention can also other Reduk besides the mentioned sugars contain agents or reduction aids, such as sodium dithionite, buffer systems, Complexing agent or the like.  

The reduction is expediently under alkali conditions carried out in aqueous solution, pH values <11, in particular, are particularly advantageous special from 11 to 12.5.

The invention sees in a particularly advantageous Wei se, the reduction at at least 50 ° C, preferably to carry out at 80 ° C to 100 ° C.

The invention advantageously provides Concentrations from 1 to 50 g / l, preferably from 10 to 30 g / l to provide the reducing agent.

The invention also relates to dyeing processes or printing on cellulosic textile material lien with dyes from the group consisting of Sulfur or vat dyes, the color fabrics according to the aforementioned invention Process in the water-soluble, fiber-affine Leuco form be transferred.

In connection with the present invention who the mate under cellulose-containing textile materials rialien understood the cellulose fibers and given if necessary fibers from other materials, for example wise semi-synthetic or fully synthetic Contain substances such as cellulose acetates, polyolefi ne, polyacrylonitrile, polyester or polyamide.

The process according to the invention for dyeing or loading print from cellulosic textile materials summarizes the aforementioned reduction according to the invention  Using isomaltulose or an isomaltulose and Reducing agent containing trehalulose, wherein the dye before, during or after the reduction which is applied to the textile material to be dyed becomes. Following the application and reduction the dye is oxidized again and there with fixed on the textile material, with which he desired color development and authenticity of the colored Textile material is achieved. The oxidation will advantageously by means of gaseous oxygen or by using oxidizing salts leads.

Advantageously, the invention provides that Reducing agents to be used according to the invention ter ultrasonic exposure to reduce the bringing dye during the dyeing process to use.

The invention is based on the figures and the related embodiments explained in more detail. It demonstrate:

Fig. 1 is a graph of reflectance values (sulfur dyes),

Fig. 2 is a graph of reflectance values (vat),

Fig. 3 is a graphical representation of the setting of the redox potential of various sugar solutions in aqueous alkaline medium and

Fig. 4 is a graphical representation of the reduction kinetics of a sugar mixture of isomaltulose, trehalulose and other sugars such as glucose, isomaltulose and glucose.

example 1 Dyeing textile materials using sulfur dye material

Using the Turbomat laboratory dyeing machine from the company Ahiba's Bat is (washed and alkaline washed boils) made of cotton with 10% Immedialschwarz CBR, liquid, colored. The dye was removed during the Apply to the textile material with a reduc agent reduced to water-soluble form. The The procedure is usually the same technology used (strongly alkaline, at 40 ° C warmed up to 100 ° C, the reaction time at 100 ° C is 1 hour). The fleet ratio was 1:10.

In a comparative experiment was used as a reducing agent use an aqueous glucose solution (10 g / l) det.

Experiment 1 (trehalulose, isomaltulose) was carried out with egg a reducing agent of the following composition  carried out: 17.5% by weight fructose, 14.9% by weight Glucose, 19.5% by weight isomaltulose, 41.5% by weight Tre halulose, 3.1% by weight isomaltose, 3.2% by weight higher Oligomers (including reversion products), 0.3% by weight of unidentified residues (based on Dry matter) (concentration of reducing agent means: 14 g / l aqueous solution).

Experiment 2 (trehalulose, isomaltulose, sucrose) was with a reducing agent of the following Zu composition carried out: 12.3% by weight fructose, 9.7% by weight glucose, 10.4% by weight sucrose, 19.5% by weight isomaltulose, 41.5% by weight trehalulose, 3.1% by weight isomaltose, 3.2% by weight higher oligomers (including reversion products), 0.3% by weight unidentified residues (based on dry sub punch) (concentration of the reducing agent: 14 g / l aqueous solution). From this reducing agent the one used in experiment 1 by hydrolysis Produce reducing agents.

Results A. Color difference measurement (according to CIE Lab) on the colored Textile substrate

Trial 1

Trial 1

Trial 2

Trial 2

Table 1 and Table 2 show the results of the Color difference measurement according to DIN 5033 / Part 1 and DIN 6174. Mean: DC difference of purity be drawing color, DH difference in color, DE total color difference (at DE <2 is a visual Difference), DL brightness difference, As the color difference of the red-green axis and Db color difference reference of the yellow-blue axis. Tables 1 and 2 it can be seen that the DE value in both Color difference measurement of experiment 1 / glucose ver same as with that of experiment 2 / glucose ver is equal to less than 2, so that a color difference the colored textiles are not visually recognizable is cash.

B. Color emission

Color emission measurements on the dyed textile material led to the results shown in FIG. 1 (Iso: isomaltulose, Tre: trehalulose). The course of the color emission values determined in the reductions according to the invention corresponds approximately to that of the comparison method, although slightly higher reflectance values were observed.

C. Color fastness

Table 3 shows the results of Be moods of wash fastness, sweat fastness and fastness to rubbing.

• 1.) Determination of wash fastness (60 ° C) according to DIN EN 20 105, part CO3
• 2.) Determination of wash fastness (95 ° C) according to DIN EN 20 105, part CO5
• 3.) Determination of perspiration fastness according to DIN 54 020
• 4.) Determination of rub fastness according to DIN EN ISO 105-X 12

Textile material

Batiste 100 CO (cotton), color black  

Color fastness

Color fastness

Table 3 shows that the means by which he He used reducing agents according to the invention aimed color fastness of those achieved with glucose Match color fastness.

D. Determination of the translucent color numbers of the colors brisk after finishing coloring

See-through color numbers

See-through color numbers

Table 4 shows the results at the determination of the see-through color numbers from the Color liquor were achieved after dyeing. Here too, when using the inventions According to the method determined data that of the Settlement procedure.

Example 2 Dyeing textile materials using vat dye fabrics Material used

Textile material: 100% CO fabric (cotton, raw white, ready for dyeing)
Sample weight: 8.5 g
Dye: Indigo pure (BASF)
Dye insert: 4 g / l
Tools:
5 ml / l NaOH
3 g / l sodium dithionite
(Reducing agent)
Neck of the trunk:
80 ml soft water
4 g pure indigo (BASF)
5 ml NaOH
3 g / l sodium dithionite
Make up to 100 ml with soft water.

execution

The indigo powder is suspended in 50 ml of water. Sodium hydroxide solution is added to 30 ml of water concluding as reducing agent sodium dithionite given. Both the dye and the auxiliary medium batch are heated to 50 ° C and in a Be Glass (200 ml volume) transferred. This approach is made up to 100 ml and 30 min. at 50 ° C. dressed up.  

Dyeing bucket

In a beaker (1500 ml volume), 800 ml Water heated to 50 ° C, with sodium hydroxide solution and natri umdithionite pretreated, the trunk vat added and then made up to 1000 ml. Colored was in two 10 minute trains.

A. Coloring without reducing agents

The staining was as described above led, but no reducing agent turned on was set. This attempt serves as a control investigation.

The fleet was observed to be dark blue in color it kept appearance. When introducing Textilma no dyeing was observed in the dye bath be respected. It was just an easy affair dirty the textile material found.

B. Staining with sodium dithionite as a reducing agent tel

The staining was as described above led, but as a reducing agent sodium dithionite was used. This attempt served as a comparison to the method according to the invention.

It was observed that the liquor after 15 minutes Shed a yellowish color and its surface slightly metallic blue color  pointed. The inserted textile material shows a deep blue color in the air passage.

C. Staining with the reducing agent according to the invention containing isomaltulose and trehalulose (Ver such 1)

The coloring was described by means of the above procedure. Instead of natri umdithionite became a reducing agent 17.5% by weight fructose, 14.9% by weight glucose, 19.5% by weight isomaltulose, 41.5% by weight trehalulose, 3.1% by weight isomaltose, 3.2% by weight higher oligomers (including reversion products) 0.3% by weight unidentified residues (based on dry sub stamping) used. The reducing agent was in a concentration of 10 g / l, 20 g / l and 30 g / l used.

It was observed that the liquor after the addition of the reducing agent used according to the invention and then vatting a blue-green color assumed. Applied textile materials showed a blue color in the air passage, but essential lighter than the sodium dithionite vat fell. With increasing use of the reduction the depth of color decreased by means of.

D. Coloring with the reducing agent according to the invention tel containing isomaltulose, trehalulose and sac charose (experiment 2)

The test conditions corresponded to the above described test conditions. Instead of Na triumdithionite was a reducing agent 12.3% by weight fructose, 9.7% by weight glucose, 10.4% by weight sucrose, 19.5% by weight isomaltulose, 41.5% by weight trehalulose, 3.1% by weight isomaltose, 3.2% by weight higher oligomers (including rever ion products) and 0.3% by weight of unidentified Leftovers used. The reducing agent was in egg A concentration of 10 g / l, 20 g / l and 30 g / l used.

It was observed that the liquor after the addition of the reducing agent used according to the invention and then vatting a blue-green color assumed. Applied textile materials showed a blue color in the air passage, but essential lighter than the sodium dithionite vat fell. With increasing use of the reduction the depth of color decreased by means of.

E. Staining with the reducing agent according to the invention containing trehalulose, isomaltulose and sac charose under the influence of ultrasound

The test conditions and the test approach ent spoke to those described under D). In addition ultrasound was used. It has been observed that the fleet after the addition of the invention ß reducing agent and then vat took on a blue-green color. The brought in Textiles showed a blue color that was significant  darker than the color without using Ultra sound failed. With increasing use of the Re the depth of color decreased.

The following table explains the experimental approaches:  

Experimental approaches

Experimental approaches

The tests listed in Table 5 and provided with test codes led to the results shown in FIG. 2.

The reflectance values with the inventive Procedures achieved outperformed those with Sodium dithionite were achieved.

Authenticity check

The authenticity test shows the resilience a coloring against the effects of the textile pro production (fastness to manufacture) and in use (Ge authenticity).

Authenticity check

Authenticity check

Both rub fastness and wash fastness the reducing agent used according to the invention can be regarded as good and those with sodium dithionite achieved comparable.

Example 3 Setting the redox potential E

Example 3 illustrates that isomaltulose or Mixtures containing isomaltulose have the same redox potential set weight faster than others Sugar like glucose.

At a pH of 12.2 (KOH 25%) and one Temperature of 20 ° C was the setting of the Equilibrium of the redox potential E of each 1.5 molar solutions compared to Ag / AgCl / KCl (3 M, E * = 210 mV vs SHE, 20 ° C) were examined. The un examined 1.5 molar solutions contained a) isomaltulose and b) contain isomaltulose nes sugar mixture (isomaltulose, fructose, glucose, Trehalulose, isomaltose). As reference substances served c) glucose, d) fructose, e) oxidized iso maltulose and f) trehalulose.

The Fig. 3 it can be seen that the re-setting doxpotential equilibrium at isomaltulose and isomaltulose-containing mixtures after a few minutes, while setting the Re doxpotential equilibrium punch significantly longer, on Vergleichssub namely, takes several hours. Oxidized isomaltulose shows an increased rate of adjustment of the redox potential equilibrium compared to the comparison substances.

Example 4 Reduction of sulfur / black

This example shows that isomaltulose or mixtures containing isomaltulose (isomaltulose, Treha lulose, glucose, fructose, isomaltose) to a he considerably faster reduction of sulfur dye are able as the reference substance Glucose.

In FIG. 4, the time period within which a complete dye reduction is achieved in function of the ratio of reducing carbonyl groups of the reducing agent for color molar applied.

Fig. 4 shows that a complete reduction of pretreated Diresul Liquid Black RDT (Clariant) with isomaltulose or isomaltulosehalti mixtures at 50 ° C takes place considerably faster than when using glucose as reducing agent tel. The originally soluble dye Diresul Liquid Black RDT was converted into the absolutely sulfide-free and thus insoluble form before the examination. This dye used for the investigation is completely insoluble in a strongly alkaline and reductant-free aqueous solution at 50 ° C.

Therefore, FIGS. 3 and 4 illustrate that the reducing agent used in the invention weight allows for faster adjustment of the redox potential DC and thus a temporally shortened reduction of dyes is obtained.

Claims (12)

1. Process for the reduction of dyes from the Group consisting of sulfur dyes and vat dyes, the reduction in aqueous al potassium medium with isomaltulose or an iso mixture containing maltulose as a reducing agent is carried out. 2. The method according to claim 1, characterized in net that the reducing agent additionally Trehalulo se, isomaltose, sucrose, glucose, fructose or Has carbohydrate oligomers. 3. Method according to one of the preceding claims che, characterized in that the reducing agent tel 10 to 90% by weight trehalulose, 10 to 90% by weight Isomaltulose, 0 to 15% by weight sucrose, 0 to 20% by weight Fructose, 0 to 20% by weight glucose, 0 to 5% by weight Isomaltose and 0 to 5 wt .-% carbohydrate oli gomers (based on the dry matter) ent holds. 4. The method according to any one of the preceding claims che, characterized in that the reducing agent tel 42% by weight trehalulose, 20% by weight isomaltulose, 10% by weight sucrose, 12% by weight fructose, 10% by weight  Glucose, 3% by weight isomaltose and 3% by weight oligomers (based on the dry matter) contains. 5. The method according to any one of claims 1 to 3, because characterized in that the reducing agent 42% by weight trehalulose, 20% by weight isomaltulose, 17% by weight fructose, 15% by weight glucose, 3% by weight iso maltose and 3% by weight carbohydrate oligomers (based on the dry matter) contains. 6. The method according to any one of the preceding claims che, characterized in that the aqueous-al potassium medium has a pH <11. 7. The method according to any one of the preceding claims che, characterized in that the reduction in at least 50 ° C, preferably 80 ° C to 100 ° C to be led. 8. The method according to any one of the preceding claims che, characterized in that the reduction un ultrasound exposure takes place. 9. Process for dyeing or printing cellulo containing textile materials with dyes the group consisting of sulfur dyes or Vat dyes, the first being water insoluble dye applied to the textile material brings, the dye according to one of the methods according to one of claims 1 to 8 and reduced is finally oxidized.   10. Process for dyeing or printing cellu loose textile materials with dyes the group consisting of sulfur dyes or Vat dyes, the first being water insoluble dye according to any one of claims 1 to 8 reduced, then applied to the material and is then oxidized. 11. Process for dyeing or printing cellu loose textile materials with dyes the group consisting of sulfur dyes or Vat dyes, the first being water insoluble dye according to any one of claims 1 to 8 reduced and at the same time based on the material brought and then oxidized. 12. The method according to any one of claims 9 to 11, characterized in that the dyeing or loading printing takes place under the influence of ultrasound.